In the case of this volume, the series title 'Musical Expeditions' refers not only to more or less forgotten composers but also to the different types of variations. In addition to representatives of the 'theme and variations' type familiar from the Viennese classics, that is, variations on a melody, Baroque bass variations (folia, chaconne, ground) are also included in the selection, which contains music from four centuries. A work with a large number of variations would probably be beyond the intellectual and physical capabilities of music school children, so the material in this volume is restricted to shorter pieces containing just a few variations and thus easier for young learners to grasp and digest.